New crystal-chemical data for marecottite

J 2015

New crystal-chemical data for marecottite

PLÁŠIL, Jakub a Radek ŠKODA

Základní údaje

Originální název

New crystal-chemical data for marecottite

Autoři

PLÁŠIL, Jakub (203 Česká republika, garant) a Radek ŠKODA (203 Česká republika, domácí)

Vydání

Mineralogical Magazine, Middlesex, Mineralogical Society, 2015, 0026-461X

Další údaje

Jazyk

angličtina

Typ výsledku

Článek v odborném periodiku

Obor

10500 1.5. Earth and related environmental sciences

Stát vydavatele

Velká Británie a Severní Irsko

Utajení

není předmětem státního či obchodního tajemství

Impakt faktor

Impact factor: 2.212

Kód RIV

RIV/00216224:14310/15:00087128

Organizační jednotka

Přírodovědecká fakulta

DOI

http://dx.doi.org/10.1180/minmag.2015.079.3.10

UT WoS

000364195000009

Klíčová slova anglicky

Marecottite; uranyl sulfate; zippeite group; crystal structure; chemical composition; hydrogen bonds

Štítky

AKR, rivok

Změněno: 7. 4. 2016 13:20, Ing. Andrea Mikešková

Anotace

V originále

Marecottite, ideally Mg-3[(UO2)(4)O-3(OH)(SO4)(2)](2)(H2O)(28), a triclinic, Mg-dominant member of the zippeite group, was described originally from a small uranium deposit at La Creusaz in Wallis (Switzerland). It has recently been found at Jachymov (Czech Republic), where it forms exceptional crystals, up to 0.3 mm across. According to an electron microprobe study of these crystals, marecottite from Jachymov is chemically similar to the material from the La Creusaz deposit. However, the Jachymov crystals exhibit more cation substitution (Zn2+ and Mn2+ for Mg2+). The chemical composition of marecottite from Jachymov corresponds to the empirical formula [(Na0.05K0.07)(Sigma 0.12) (Mg1.83Zn0.41Mn0.41Cu0.15Ni0.08)(Sigma 2.88)Al-0.07](Sigma 3.07)(UO2)(8)[(SO4)(3.77)(SiO4)(0.21)](Sigma 3.98)O-6(OH)(1.84).28H(2)O (the mean of four representative spots; calculated on the basis of eight U atoms and 28 H2O per formula unit and 1.84 OH for charge balance). According to single-crystal X-ray diffraction, marecottite from Jachymov is triclinic, P (1) over bar, a = 10.8084(2), b = 11.2519(3), c = 13.8465(3) angstrom, alpha = 66.222(2), beta = 72.424(2), gamma = 70.014(2)degrees, V = 1421.57(6) angstrom(3) and Z = 1. The crystal structure was refined from a highly redundant dataset (30,491 collected reflections) to R-1 = 0.0367 for all 7042 unique reflections. The refined structure confirms the previously determined structure for the crystal from the La Creusaz deposit. An extensive network of hydrogen bonds is an important feature that keeps the whole structure together, but the positions of H atoms had not been determined previously. The H-bond scheme proposed based on a detailed bond-valence analysis and the role of different types of molecular H2O in the structure is discussed.

Citovat

PLÁŠIL, Jakub a Radek ŠKODA. New crystal-chemical data for marecottite. Mineralogical Magazine. Middlesex: Mineralogical Society, 2015, roč. 79, č. 3, s. 649-660. ISSN 0026-461X. Dostupné z: https://dx.doi.org/10.1180/minmag.2015.079.3.10.

@article{1340744,
   author = {Plášil, Jakub and Škoda, Radek},
   article_location = {Middlesex},
   article_number = {3},
   doi = {http://dx.doi.org/10.1180/minmag.2015.079.3.10},
   keywords = {Marecottite; uranyl sulfate; zippeite group; crystal structure; chemical composition; hydrogen bonds},
   language = {eng},
   issn = {0026-461X},
   journal = {Mineralogical Magazine},
   title = {New crystal-chemical data for marecottite},
   volume = {79},
   year = {2015}
}

TY  - JOUR
ID  - 1340744
AU  - Plášil, Jakub - Škoda, Radek
PY  - 2015
TI  - New crystal-chemical data for marecottite
JF  - Mineralogical Magazine
VL  - 79
IS  - 3
SP  - 649-660
EP  - 649-660
PB  - Mineralogical Society
SN  - 0026461X
KW  - Marecottite
KW  - uranyl sulfate
KW  - zippeite group
KW  - crystal structure
KW  - chemical composition
KW  - hydrogen bonds
N2  - Marecottite, ideally Mg-3[(UO2)(4)O-3(OH)(SO4)(2)](2)(H2O)(28), a triclinic, Mg-dominant member of the zippeite group, was described originally from a small uranium deposit at La Creusaz in Wallis (Switzerland). It has recently been found at Jachymov (Czech Republic), where it forms exceptional crystals, up to 0.3 mm across. According to an electron microprobe study of these crystals, marecottite from Jachymov is chemically similar to the material from the La Creusaz deposit. However, the Jachymov crystals exhibit more cation substitution (Zn2+ and Mn2+ for Mg2+). The chemical composition of marecottite from Jachymov corresponds to the empirical formula [(Na0.05K0.07)(Sigma 0.12) (Mg1.83Zn0.41Mn0.41Cu0.15Ni0.08)(Sigma 2.88)Al-0.07](Sigma 3.07)(UO2)(8)[(SO4)(3.77)(SiO4)(0.21)](Sigma 3.98)O-6(OH)(1.84).28H(2)O (the mean of four representative spots; calculated on the basis of eight U atoms and 28 H2O per formula unit and 1.84 OH for charge balance). According to single-crystal X-ray diffraction, marecottite from Jachymov is triclinic, P (1) over bar, a = 10.8084(2), b = 11.2519(3), c = 13.8465(3) angstrom, alpha = 66.222(2), beta = 72.424(2), gamma = 70.014(2)degrees, V = 1421.57(6) angstrom(3) and Z = 1. The crystal structure was refined from a highly redundant dataset (30,491 collected reflections) to R-1 = 0.0367 for all 7042 unique reflections. The refined structure confirms the previously determined structure for the crystal from the La Creusaz deposit. An extensive network of hydrogen bonds is an important feature that keeps the whole structure together, but the positions of H atoms had not been determined previously. The H-bond scheme proposed based on a detailed bond-valence analysis and the role of different types of molecular H2O in the structure is discussed.
ER  -

PLÁŠIL, Jakub a Radek ŠKODA. New crystal-chemical data for marecottite. \textit{Mineralogical Magazine}. Middlesex: Mineralogical Society, 2015, roč.~79, č.~3, s.~649-660. ISSN~0026-461X. Dostupné z: https://dx.doi.org/10.1180/minmag.2015.079.3.10.

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